Most household filing advice is about tidiness. That is the wrong frame. Nobody has ever needed a tidy drawer. People need one document, immediately, usually while somebody is on the phone asking for a policy number.
The short list
Passports and birth certificates. Insurance policies, with the claims number. The mortgage or the lease. Vehicle titles and registration. Appliance and HVAC warranties with their serial numbers. Wills and powers of attorney, and where the originals physically are.
That is the set. Everything else is archive, and archive can stay in a box.
Findable beats organized
The test is not whether the drawer looks good. It is whether a second adult in the house can produce the insurance policy in two minutes without calling the first. If they cannot, the filing system has failed regardless of how neat it is.